[dad911]

I used the kit for my tankless, makes it easy to flush.

https://smile.amazon.com/Rheem-RTG20220AB-Webstone-Tankless-Service/dp/B00C5YBENQ/ref=sr_1_3?dchild=1&keywords=Webstone+3%2F4+in+Brass+Tankless+Water+He ater+Service+Valve&qid=1621467875&sr=8-3

Are you going to copper or pex?

If copper I'd use the water heater supply flexible lines with sharkbite ends.